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High-voltage wires have no insulating surface, will they leak electricity in rainy days?

Release time:

2023-03-07

The voltage used by electrical appliances in general households is only 220 volts, but for safety, it is wrapped with a thin layer of insulation to prevent it from contacting the live wire, thereby preventing electric shock.

The voltage used by electrical appliances in general households is only 220 volts, but for safety, it is wrapped with a thin layer of insulation to prevent it from contacting the live wire, thereby preventing electric shock. The transmission voltage of high-voltage transmission lines is mostly above 10,000 volts, and the voltage of some lines is as high as 100,000 volts or 500,000 volts, and there is no insulating surface. So, will the high-voltage line leak electricity in rainy days?

Open spaces: keep a safe distance

Usually, the voltage of the wires at home is only 220 volts. As long as they are wrapped with a thin layer of insulation to prevent people from contacting the live wire, electric shock can be prevented. And this kind of insulator is just a decoration for high-voltage lines. For high-voltage transmission lines with a transmission voltage above 10 kV, the thickness of the insulation layer of ordinary wires is far from enough.

In the face of high voltage, air can break down and conduct electricity, and insulators are useless. Under normal circumstances, a high voltage of 10 kV can break down the air conduction of more than 1 cm. People standing a certain distance next to high-voltage equipment will still cause electric shock even if they do not touch it. Therefore, the state stipulates that the construction of high-voltage transmission lines must be far away from the ground and buildings. Tens of meters away from the ground, built in an open no-man's land, with a sufficient safety distance, the probability of electric shock accidents is extremely small. Therefore, through these measures, the high-voltage transmission line can increase the space distance from the ground, which can well ensure safety.

Rainy day: does not form a complete circuit

Although water conducts electricity, rainwater is not connected. The rain we see is actually the afterimage left by the rain falling too fast. The rain actually comes in drops with no small air gap between them, so the rain is not conductive. Since a complete loop is not formed between the high-voltage line and the ground, the high-voltage electricity will not be introduced into the ground through raindrops to form a short circuit.

Insulators: prevent the flow of electricity

There is a ceramic insulator between the high-voltage wire and the iron tower. Its surface is smooth and will not accumulate water. Its function is to prevent the flow of current between the high-voltage wire and the iron tower. If there is no insulator, the high-voltage current will be guided into the ground along the iron tower. The withstand voltage margin of the insulator is very sufficient, and its disk-shaped structure greatly increases the creepage distance of the arc. In fact, insulators are not afraid of being wet by rain, but rain can clean the conductive dust on them.

It is set up in an open area, rainwater cannot be connected into a circuit, and there are insulators to protect it, so even in rainy days, high-voltage lines without insulation will not leak electricity. Besides, with the continuous improvement of power system systems, regulations and technologies over the past two decades, electric shock accidents have been greatly reduced. The general public has few opportunities to come into contact with voltage levels above 10kV, and electric shock accidents at voltage levels above 10kV rarely occur. . Therefore, there is no need to use insulated wires for such high-voltage lines. This time, friends, you can rest assured! However, Xingsheng Cable still wants to remind you that no matter when the sun is shining in the sky, when there is lightning and thunder, or when there is a storm, we must keep a sufficient safe distance from high-voltage lines, please pay attention to safety!

Key words:

Power Cable

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